Receiving device, recording and reproducing device and receiving/recording-reproducing system for digital broadcast signal

• US 6,674,858 B1
• Filed: 12/10/1998
• Issued: 01/06/2004
• Est. Priority Date: 12/10/1997
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Takeuchi, Toshifumi, Arai, Takao, Kimura, Hiroyuki
• Primary Examiner(s): Barrón, Gilberto
• Assistant Examiner(s): Zand, Kambiz
• Application Number:
  US09/208,443
• Time in Patent Office: 1,853 Days
• Field of Search: 705/57-58, 380/201, 380/203, 380/210, 380/217, 380/239-241, 713/176, 713/193
• US Class Current: 380/202
• CPC Class Codes: H04N 2005/91328 the copy protection signal being a copy management signal, e.g. a copy generation management signal [CGMS]
• CPC Class Codes: H04N 2005/91335 the copy protection signal being a watermark
• CPC Class Codes: H04N 2005/91364 the video signal being scrambled
• CPC Class Codes: H04N 21/4334 Recording operations recording of a television signal H04N5/76; arrangements for recording or accumulating broadcast information or broadcast-related information H04H60/27
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/4408 involving video stream encryption, e.g. re-encrypting a decrypted video stream for redistribution in a home network
• CPC Class Codes: H04N 21/4623 Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 21/4627 Rights management associated to the content security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 21/8355 involving usage data, e.g. number of copies or viewings allowed
• CPC Class Codes: H04N 21/8358 involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

A receiving device comprises a signal demodulator circuit for demodulating an encrypted video signal and attribute information including information for decoding an encryption, an attribute information identifying circuit for identifying and outputting the attribute information, and a descramble circuit for unscrambling the video signal obtained from the signal demodulator circuit, based on the output produced from the attribute information identifying circuit. A signal re-scrambled in accordance with a device ID signal is recorded in a recording and reproducing device. Further, the recording of the signal is controlled based on the output obtained from the attribute information identifying circuit.

Claims

1. A receiving device, comprising:

a signal demodulator circuit for demodulating an encrypted video signal and attribute information including an encryption key and a channel key indicative of each broadcast channel;

a channel key detection circuit for detecting a channel key from the attribute information;

an encryption key detection circuit for detecting an encryption key from the attribute information;

a device ID generating circuit for generating a unique device ID signal;

a channel key selection circuit for selecting a channel key for a receivable channel according to the device ID signal and the channel key from the channel key detection antenna and outputting the selected channel key;

a decryption circuit for outputting a decryption key from the channel key outputted from said channel key selection circuit and the encryption key; and

a descramble circuit for unscrambling the video signal obtained from said signal demodulator circuit by using the decryption key, and

wherein the output of said descramble circuit is outputted for recording.

2. A receiving device, comprising:

a signal demodulator circuit for demodulating an encrypted video signal and attribute information including information for decoding an encryption;

an attribute information identifying circuit for identifying and outputting the attribute information; and

a descramble circuit for descrambling the video signal obtained from said signal demodulator circuit according to the output obtained from said attribute information identifying circuit, and

wherein the output of said descramble circuit is outputted for recording; and

wherein the receiving device further includes an electronic watermark, which is embedded in the video signal, processing circuit, and wherein a CGMS signal, which is superimposed in a vertical blocking area, obtained from said electronic watermark processing circuit is outputted to a recording device to control copying of said recording device.

3. A receiving device, comprising:

a signal demodulator circuit for demodulating an encrypted video signal and attribute information including each encryption key and each channel key indicative of a broadcast channel;

a channel key detection circuit for detecting a channel key from the attribute information;

an encryption key detection circuit for detecting an encryption key from the attribute information;

a device ID generating circuit for generating a unique device ID signal;

a channel key selection circuit for selecting a channel key for a receivable channel according to the device ID signal and the channel key from the channel key detection circuit and outputting the same therefrom;

a decryption circuit for outputting a decryption key from the channel key outputted from said channel key selection circuit and the encryption key;

a descramble circuit for unlocking the scramble of the video signal obtained from said signal demodulator circuit, based on the decryption key; and

a re-scramble circuit for re-scrambling the descrambled video signal using the encryption key, and

wherein the output of said re-scramble circuit is outputted for recording.

4. The receiving device according to claim 3, further including a format conversion circuit for converting the descrambled video signal into a format which matches with a recording medium to record the video signal thereon;

wherein said re-scramble circuit re-scrambles the output of said format conversion circuit.

5. A receiving device, comprising:

a signal demodulator circuit for demodulating an encrypted video signal and attribute information including each encryption key and each channel key indicative of a broadcast channel;

a channel key detection circuit for detecting a channel key from the attribute information;

an encryption key detection circuit for detecting an encryption key from the attribute information;

a device ID generating circuit for generating a unique device ID signal;

a channel key selection circuit for selecting a channel key for a receivable channel channel according to the device ID signal and the channel key from the channel key detection circuit and outputting the same therefrom;

a decryption circuit for outputting a decryption key from the channel key outputted from said channel key selection circuit and the encryption key;

a descramble circuit for unscrambling the video signal obtained from said signal demodulator circuit, based on the decryption key; and

a re-scramble circuit for re-scrambling the descrambled video signal,

wherein the output of said re-scramble circuit is outputted for recording.